In the fabrication of semiconductor integrated circuit (IC) devices, various device features such as insulation layers, metallization layers, passivation layers, etc., are formed on a semiconductor substrate. It is known that the quality of an IC device fabricated is a function of the processes in which these features are formed. The yield of an IC fabrication process, which in turn is a function of the quality of the device fabricated and a function of the cleanliness of the manufacturing environment in which the IC device is processed.
The ever increasing trend of miniaturization of semiconductor IC devices requires more stringent control of the cleanliness in the fabrication process and the process chamber in which the process is conducted. In recent years, contamination caused by particles or films has been reduced by the improvements made in the quality of clean rooms and by the increasing utilization of automated equipment which are designed to minimize exposure to human operators. However, even though contaminants from external sources have been reduced, various contaminating particles and films are still generated inside the process chamber during the processing of semiconductor wafers. Therefore, attention has been drawn to an effective chamber cleaning method.